Spark plug replacement - tools needed

Could be real or could be imagined. If it is true then your engine would have to be operating more efficiently, so I'd expect to see a noticeable increase in MPG too. So to be honest, unless you also notice a corresponding MPG increase then it's probably "all in your head".

 

I'll let you know. I just changed them yesterday. You wouldn't believe the rust I had on the top part of the plugs and threads. No more engine wash-down for me.

DROID RAZR ? 2

 

Yeah, that little "channel" in the top of the valve cover really is a nice trap for water isn't it. I used an funnel with an over-sized opening to fill the oil one time and accidentally filled that space up with oil.

 

I just got the chance to drive on the highway and I can without a doubt tell you that there is a huge difference in acceleration. It feels more powerful and "brisk". Like the car is new again. I currently have 87.5K miles. I just wanted to change the plugs early and now I'm glad I did.

The water damage to my plugs may have affected its performance. Who knows.

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The roads slope up to our house and I noticed it too. On the other hand, the fuel economy has not gone up.

 

You guy's are making me itch to change out my plugs now.

I've got a new set here ready to go, but I've been waiting for my 200,000km (125k mile) service to do it. Currently I'm at 175,000 km.

 

Do it! Plugs are cheap. I went with the factory Denso. Use a torque wrench and do not use anti-seize.

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Thank you everyone very much for sharing your experiences. I changed my plugs yesterday with that special advanced auto magnetic spark plug tool without removing the cowl. I felt this job was easier than changing the oil for me. My Prius has 128k on it and the plugs were worn but not that bad. I don't think it was urgent for me to change it. I don't think I feel any performance increase or anything after changing the plugs. But I also don't feel any change after changing the oil. Thanks again.

 

I also just changed my plugs thanks to all of the great advice in this thread. I picked up the magnetic socket from Advance and it made it super simple. Took me 40 min including cleanup.

One thing I noticed is that the existing plugs were NGK. Does that mean they had been changed before? I'm at 141K, and I bought the car with 100K.

Here are a couple of photos:

 

BTW.. Advanced sells the Denso now ($9) but I went with NGK ($7)

 

NGK and Denso both provide original equipment iridium plugs to Toyota for the Prius. The old plug in your photos had accumulated sufficient deposits so I would say it had not previously been replaced.

 

Other than the slightly rough appearance from the deposits, the electrodes look very well shaped. That makes me wonder whether the plugs can still be used for a very long time.

 

I wasn't experiencing any issues, just did it because, well it seemed like I should.

 

Oh my, wish me luck ill do mine tomorrow morning ( feeling nervous)

 

Oh my, ill do mine tomorrow morning... Wish me luck! ( feeling nervous)

 

Hi! May I ask, why not use anti seize? I'll be replacing mine tomorrow morning..

 

It's not really necessary as the threads of the plugs are already plated. Also, anti-seize can fall into plug hole. I didn't use it.

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Check the plug manufacturer web site. Some manufacturers specifically recommend not to use anti-seize on some plated plugs.

 

I'll be using ngk laser iridium 4996.

 

Attached an old PDF from NGK.